Polyacetal polymers, which are commonly referred to as polyoxymethylene polymers, have become established as exceptionally useful engineering materials in a variety of applications. Polyoxymethylene polymers, for instance, are widely used in constructing molded parts, such as parts for use in the automotive industry and the electrical industry. Polyoxymethylene polymers have excellent mechanical properties, fatigue resistance, abrasion resistance, chemical resistance, and moldability.
Although polyoxymethylene polymers have excellent physical characteristics, the polymers are typically not amenable to many printing or painting processes. For instance, due to a low surface energy and high crystallinity, polyoxymethylene polymers are not receptive to many paints and printing inks. Printing inks, for instance, do not sufficiently adhere to the surface of the polymer for many applications. While attempts have been made to pretreat the surface of the polymer to improve ink adhesion, such as corona discharge, UV irradiation, or e-beam irradiation, followed by printing with UV curable inks, this requires additional time and is an added expense in the manufacturing of articles molded from polyoxymethylene polymers.
In view of the above, a need exists for a polyoxymethylene polymer composition and to a process for molding polyoxymethylene articles that have greater affinity and adhesion to paints and inks without the need for pretreating the polymer surface.